1. Technical Field
The present invention is related to an active material, in particular to an active material comprising the lithium metal.
2. Description of Related Art
In order to provide the power, the proper active materials must be applied for the power supply system to convert the chemical energy into the electrical energy. For example, the common active materials applied for the lithium battery contain the lithium, carbon and so on, wherein the lithium metal has the highest energy density. However, the lithium metal has high chemical activity so that the storage and operation conditions must be maintained severely since the lithium metal reacts with the oxygen and moisture in the surroundings immediately after contacting. The conditions of storage and operation must be controlled in low moisture, few oxygen and proper temperature and humidity so that the cost of process gets higher. Since, the lithium metal is so active, the excite oxidation-reduction reaction occurs under improper conditions, which sometimes would turn into the combustion reaction.
As known, in order to increase the reaction surface area of the electrode of the power supply system, the particle size of the lithium is in the scale of micrometer or nanometer. A lithium carbonate shell is exerted for covering the lithium metal in the scale of micrometer or nanometer for solving the difficulties in storing and operating. However, the smaller the particle is the severer reaction occurs. Hence, during the slurry mixing, the low-polarity solvent, such as toluene, is required to avoid the reaction between the lithium and the NMP/PVDF solvent. But the low-polarity solvent is harmful for the human and the environment.
Accordingly, an active material is provided to overcome the above problems.